Metagenomic next-generation sequencing in the diagnosis of neurocysticercosis:A case report

BACKGROUND The clinical symptoms and imaging manifestations of neurocysticercosis(NCC)are very different,and the difficulty and delay of clinical diagnoses may lead to an increase in mortality and disability.Rapid and accurate pathogen identification is important for the treatment of these patients.Metagenomic next-generation sequencing(mNGS)is a powerful tool to identify pathogens,especially in infections that are difficult to identify by conventional methods.CASE SUMMARY A 43-year-old male patient was admitted due to a recurrent headache for a few months.Imaging examinations showed hydrocephalus and cystic lesions,which were considered to be a central nervous system infection,but no etiology was found by routine examination.mNGS of the cerebrospinal fluid revealed high Taenia solium reads,and the positive results of a cysticercosis antibody test confirmed the infection.Combined with the patient’s clinical manifestations,the etiological evidence,and the imaging manifestation,the patient was finally diagnosed with NCC and he was prescribed dexamethasone,albendazole,neurotrophic drugs,and intracranial pressure reduction therapy.The headaches disappeared after anti-parasite treatment,and no associated symptoms recurred prior to the three-and six-month follow-up.CONCLUSION As an accurate and sensitivity detection method,mNGS can be a reliable approach for the diagnosis of NCC.

Previously unexplored etiology for femoral head necrosis:Metagenomics detects no pathogens in necrotic femoral head tissue

BACKGROUND Osteonecrosis of the femoral head(ONFH)is a frequent and refractory disease whose pathogenesis has not yet been elucidated.Infection and other factors that reduce the local blood supply can lead to bone necrosis.AIM To aim of this study was to assess the relationship of ONFH with bone infection by use of metagenomic sequencing.METHODS Twelve patients with idiopathic ONFH and 12 comparable controls who were undergoing hip arthroplasty were followed up in parallel.Necrotic femoral head specimens were collected for bacterial and fungal cultures using standard methods.Bone specimens were subjected to preliminary processing,and metagenomics sequencing of microorganisms was performed.A one-way analysis of variance was used to compare bacterial species in the two groups.RESULTS Bacterial and fungal cultures exhibited no evidence of microbial growth in all isolated necrotic femoral head tissues.We thus performed metagenomic sequencing and classified the species as suspected pathogens or suspected background microorganisms based on known bacterial pathogenicity.There was no evidence of viruses,fungi,parasites,M.tuberculosis complex,or mycoplasma/chlamydia.There were also no significant differences in suspected pathogens or suspected background microorganisms(P>0.05).CONCLUSION Although we found no pathogens specific for ONFH in necrotic femoral head tissue,our research provides a foundation for future research on the metagenomics of bone pathogens.

Application of metagenomic next-generation sequencing in the diagnosis of infectious diseases of the central nervous system after empirical treatment

BACKGROUND The diagnostic value of metagenomic next-generation sequencing(mNGS)in central nervous system(CNS)infectious diseases after empirical treatment has not been reported.AIM To investigate the diagnostic value of mNGS of cerebrospinal fluid(CSF)in the empirically treated CNS infectious diseases.METHODS A total of 262 CSF samples from patients with suspected CNS infections were collected between August 2020 and December 2021.Both mNGS and conventional methods were used for testing.The conventional methods included microbial culture,smear,polymerase chain reaction,etc.RESULTS Among 262 suspected cases,183 cases(69.84%)were diagnosed as CNS infection,including 86 cases of virus infection(47.00%),70 cases of bacterial infection(38.25%)and 27 cases of fungal infection(14.76%).The sensitivity and specificity of mNGS were 65.6%(95%CI:58.2%-72.3%)and 89.6%(95%CI:79.1%-95.3%),respectively.The PPV of mNGS was 94.5%(95%CI:88.6%-97.6%),and the NPV was 48.8%(95%CI:39.7%–57.9%).The pathogen detective sensitivity and accuracy of mNGS were higher than those of conventional methods(Sensitivity:65.6%vs 37.2%;P<0.001;Accuracy:72.0%vs 50%,P<0.001).The results showed that compared with conventional methods,mNGS technology was a more sensitive method for the diagnosis of CNS infection after empirical treatment.CONCLUSION mNGS can be a better method applied in the diagnosis of CNS infection after empirical treatment.

Altered Motor-Striatal Plasticity and Cortical Functioning in Patients with Schizophrenia

Patients with schizophrenia undergo changes in brain plasticity. In the present study, we characterized motor cortical-striatal plasticity in such patients. Compared with the potentiation following high-frequency repetitive transcranial magnetic stimulation in the control group, the patients demonstrated impaired plasticity of corticostriatal motor-evoked potentials recorded from hand muscles.Notably, the loss of cortical plasticity was correlated with impaired motor learning in a rotary pursuit task. Moreover,the loss of plasticity was correlated with the symptoms of schizophrenia. The results suggest that the progression of schizophrenia is accompanied by altered cortical plasticity and functioning.